This guy says that he has developed a cheap and simple PDE, it looks a bit like a thermojet without intakes. Should be interesting to read more about the engine and see some video of it running since I find it very hard to believe that it is producing true detonations...

A couple of times every year I notice people that claims they have designed a "ground-breaking" engine. All of them have something in common - all their work is based on highly subjective judgements. When I have mailed and asked for objective qualitative and quantitative facts about projects they answer the questions in a non-thechnical, non-scientific way. And sometimes they give no answer.

I admire amateurs building and experiment with propulsion. And I always tries to approach them with a humble attitude. But when they claim that they solved something that professional scientist only can achieve with big money and time consuming work, and sometimes that is not enough, I take on a very sceptical position.
Particulary if someone begins the text with "All I will say is true".

This guy says that he has developed a cheap and simple PDE, it looks a bit like a thermojet without intakes. Should be interesting to read more about the engine and see some video of it running since I find it very hard to believe that it is producing true detonations...

//Anders

Well, one thing that makes me darn suspicious is that the combustion chamber is a bulb. If you have a detonation started in a bulb, I think the overpressures are great enough to blow it apart since it would likely choke at the nozzling to the output. Which isn't to say this guy isn't producing thrust by essentially creating a gas ignition cannon, but I don't think the word PDE probably fits.

I'm writing an automated airplane designer in java, useful later when you guys get ready to bolt a p-jet onto some wings

DDT- the pressure created from the deflag pressurizes the combustible gases that havent been burned and forces them to detonate. this can be seen in piston engines when they aren't given enough fuel , known as being run "lean".

Rossco wrote:Ha, thats funny, I stummbled apon this just today.
Not to say there isnt some interesting info in there.

Rossco

Well, you throw oxidiser and fuel into a combustion chamber at the end of a long barrel, and how could you not have fun? Especially when you get a real detonation in a thin wall chamber the size of a melon, that's gotta be a blast :)

I'm writing an automated airplane designer in java, useful later when you guys get ready to bolt a p-jet onto some wings

If you look through the articles you'll see alot of pretty intense looking projects this guy has worked on. Not to say that he's got a PDE sitting there, but he sure has invested alot of energy and money into developing pulsed combustors.

Looking at the guy's other project pictures, it's obvious he is a dedicated experimenter. He is working on somje pretty interesting looking stuff too. None of it looks any sillier than playing with pulsejets.

You dont know what kind of discussion I have had with this guy.
Can this guy can be a new genius in the field of propulsion? Of course he can!

The problem with this hobby is that people often claims that they are more talented than everybody else. They said they have design something new and with very high efficiency that will lead to some kind of revolution in the field of propulsion.
Often they have no clue about what they are doing. Yes, they know that they are building a engine based on newtons laws. But when it comes to theromdynamics, fluid mechanics, combustion, expressing of cycles, they have very little knowledge.

One example, I seen a couple of months ago was I guy who had design some kind of pulsejet or ramjet and decide to join a competiton held by a large US government institution(NASA?). This man shows the rejection letter on his website and all the reviewers clearly states that this man have no scientific facts about his project, no analysis what so ever.
Why did this man not include any scientific facts. I think his work where based on subjective matter and did not know how this engine really worked.
This shows the importance of a objective work based on facts.

I am comfortable with people that experiment and design amatuer propulsion. It is a fantastic hobby. I experiment with small rocket engines. BUT if you want to show of in public and brag about your work I only accept scientific facts about your design.

superhornet59 wrote:heres what ill admit. that nuclear reactor puts out a little more than the amount of power it takes to run it. so, its pretty impracticle for powering a few cities. does that mean its not a working running fusion reactor?

you bet it is. a fusion reactor, is a fusion reactor. whether it follows our typical 'toroid of plasma the size of a house' stereotype or not... it works.

The Farnsworth-Hirsch Fusor works in that it causes fusion to occur. It absolutely doesn't work in the sense of "produces more power than it consumes", at least as published. It's a neat project and all, and useful as a neutron source, but unlikely in the extreme to provide net energy; indeed, if it did produce net energy, no matter how miniscule the amount, it would solve our enegy problems at a stroke, pretty much. And it would already be in general use.

HattoriHanzo wrote:One example, I seen a couple of months ago was I guy who had design some kind of pulsejet or ramjet and decide to join a competiton held by a large US government institution(NASA?). This man shows the rejection letter on his website and all the reviewers clearly states that this man have no scientific facts about his project, no analysis what so ever.
Why did this man not include any scientific facts. I think his work where based on subjective matter and did not know how this engine really worked.
This shows the importance of a objective work based on facts.

There would have been more facts and analysis with testing. There would have been testing if the prototype had been finished and instrumentation had been aggregated. All of that could have been done with capitalization ... but by whom? That has to be by people who can take losing the money if you fail and demand a big chunk of the pie if you succeed. I never met any of those, except one ME I know who would have invested if I had obtained patent protection - but even that takes a fair chunk of cash.

I am comfortable with people that experiment and design amatuer propulsion. It is a fantastic hobby. I experiment with small rocket engines. BUT if you want to show of in public and brag about your work I only accept scientific facts about your design.

Then you must feel extremely uneasy about using most of the products found in your home! The idea of scientists inventing useful products is actually fairly new, and even today is mostly the claim of chemical and drug companies. Most things that really work are designed by, well, designers - like engineers and inventors. This makes sense because most things can be made to work by starting with basic principles and optimizing by what the textbooks used to call "a process of stepwise refinement". Such a process can be engaged AFTER you get your basic idea protected, if you can. If we had to have the sanction of qualified scientists for every technical innovation, progress would happen at a fraction of the pace we have come to accept as 'normal' in the modern world.

Of course, that doesn't excuse blatant ignorance of facts and principles that are important to get the job done, and it doesn't excuse fraudulent presentations of ideas as 'revolutionary', 'ground-breaking' or whatever. (I'm sure you can still find someone who will be glad to sell you a "100 percent efficient friction furnace" for your home, if you really want one. It will work, too ;-)